Try it...
1) firstly when going to sleep repeat the mantra, like "i will know, i,m dreaming"
This mantra has 2 purposes - you will get into focus your desire - you will eventually get tired more and more but you will not fall asleep - and this is crucial point
2) As soon as you feel you are very close to drifting off to sleep, almost sleeping.. immediately look upwards with eyes closed , roll eyes up and after a very short while (for me its matter of seconds) You will start getting dizzy and feel like everything is spinning. And there it IS - Dream Kingdom!